2-nitro-5-(halophenoxy)benzoyl chlorides

ABSTRACT

2-NITRO-5(HALOPHENOXY) BENZOIC ACIDS AND ESTERS, SALTS, AMIDES, AND ACYL HALIDES THEREOF COMPRISES A CLASS OF COMPOUNDS THAT ARE HIGHLY EFFECTIVE PRE- AND POST-EMERGENCE HERBICIDES.

. RobertJ.

. Z-NITRO-S-(HALOPHENOXDBENZOYL CHLORIDES Theissen, Westfield, N.J., assignor to Mobil Oil Corporation, New York, N.Y. 1

"N Drawing. Continuation-impart of application Ser. No

, 194,481, Nov. 1, 1971, which is a division of applica- "tion Ser. No. 819,412, Apr. 25, 1969, now Patent No. 3,652,645. This application Feb. 22, 1973, Ser. No.

334,526 H Int. Cl. C07c 79/46 US. Cl. 260-544 M ABSTRACT OF THE DISCLOSURE 2-nitro-5 (halophenoxy)benzoic acids and esters, salts,

amides, and acyl halides thereof comprise a class of compounds that are highly e'ifective preand post-emergence herbicides.

"CROSS-REFERENCE To RELATED APPLICATIONS This application is a continuation-in-part of copending a division of application Ser. No. 819,412, filed Apr. 25, 1969, now US. Pat. No. 3,652,645.

BACKGROUND OF THE INVENTION Field of the invention This invention is concerned with certain phenoxybenzoic acid chlorides and their use as herbicides.

Description of the prior art It has been proposed to use as herbicides Z-methoxybenzoic acids (US. 3,013,054) and 4-phenoxybenzoic acids (French 1,502,538). It is the discovery of this invention, however, that benzoic acids having a phenoxy substituent in the 5-position are very effective herbicides. In US. 3,475,427 is disclosed a position isomer of these benzoic acids.

SUMMARY OF THE INVENTION This invention provides herbicidal compounds having the formula:

wherein X is halogen and n is 1 to 5.

DESCRIPTION OF SPECIFICEMBODIMENTS i The compounds of this invention are readily prepared by the Ullmann ether synthesis reaction between the alkali metal (Na, K) salt of a halophenol and a 5-halo (Cl, Br)- 2-nitrobenzoic acid or an ester, amide, or salt thereof. The S-haIO-Z-nitro-benzoic acid is readily prepared, by nitrating 1a m-halotoluene, followed by oxidation of the methyl group-by well-known procedures.

Non-limiting examples of the compounds of this invention are:

method for product recovery.

application Ser. No. 194,481, filed Nov. 1, 1971, which is 3,812,184 Patented May 21, 1974 N,N-dirnethyl 2-nitro-5-(2',4,6'-trichlorophenoxy)benzamide;

sodium (or potassium) 2-nitro-5-(2',4,6'-trichlorophenoxy)benzoate;

ethylarnmonium 2-nitro-5-(2,4',6"-trichlorophenoxy) benzoate;

'ethanolammonium 2-nitro-5-(2',4,6-trichlorophenoxy) benzoate; sodium 2-nitro-5-(2',4,6'-trichlorophenoxy)benzoate; methyl 2-nitro-5- 2,4',5-trichlorophenoxy) benzoate;

methyl 2-nitro-5-(2,4'-dichlorophenoxy)benzoate; and

methyl 2-nitro-5-( 2,3 ',4',5 6'-pentachlorophenoxy) benzoate.

The following example illustrates the preparation of a typical compound of this invention and demonstrates a EXAMPLE 1 V 1 Methyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate 9 A stirred solution of methyl S-chloro-2-nitro-benzoate (17.0 g., 0.079 mole) and the potassium salt of 2,4,6-trichlorophenol (18.6 g., 0.079 mole) in dimethyl sulfoxide (100ml) was heated at for 17 hours. The cooled reaction mixture was diluted with water (500 ml.) and then extracted with ether (3X ml.). The combined ether fractions were washed with 10% sodium hydroxide solution (2X 30 ml.) and then with a saturated aqueous sodium chloride solution. The ether solution was dried (Na S0.,) and the solvent evaporated to give a dark oil. Two crystallizations (petroleum ether) gave 1.91 g. of a pale yellow solid, M.P. 10l103.

EXAMPLES 2 THROUGH 5 The ester of Example 1 was hydrolyzed to the corresponding acid and using known procedures for the preparation of acid chlorides four other compounds within the scope of this invention were prepared. These compounds are:

i 2-nitro-5-(2,4'-dichlorophenoxy)benzoyl chloride (3) 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoyl chloride (4) 2-nitro-5-(2',6'-dichlorophenoxy)benzoyl chloride (5 2-nitro-5- (2',4'-dichloro-6'-fluorophenoxy) benzoyl chloride. For comparison, there was prepared a position isomer of Example 2 the acid of which is disclosed in US. 3,475,427.

(6) 2-nitro3-(2',4'-dichlorophenoxy)benzoyl' chloride.

The compounds of this invention can be applied in various ways to achieve herbicidal action. They can be applied, per se, as solids or in vaporized form, but are preferably applied as the toxic components in pesticidal compositions of the compound and a carrier. The compositions can be applied, as dusts; as liquid sprays, or as gasepropelled sprays and can contain, in addition to a carrier, additives such as emulsifying agents, binding agents, gases compressed to the liquid state, odorants,

stabilizers, and the like. A wide variety of liquid and solid carriers can be used. Non-limiting examples of solid .carriers include talc, bentonite, diatomaceous earth, pyrophyll1te, fullers earth, gypsum, flours derived from cotton seeds and nut shells, and various natural and synthetic clays having a pH not exceeding about 9.5. Non-limiting examples of liquid carriers, include water; organic solvents, such as alcohols, ketones, amides and esters; mineral oils, such as kerosene, light oils, and medium oils and vegetable oils, such as cottonseed oil.

4 Herbicidal testing of the compounds of Examples 2 through 5 and of the comparative compounds showed the results set forth in Table I. The plants are tabulated using the following abbreviations:

In practice, herbicidal application is measured in terms 5 Crabgrass CG of ounds of herb'cide 1i d Th d grass JG p 1 app e per acre. e compoun s Barnyard grass B6 of this invention are elfective herbicides when applied Bean BN Turnip TP 1n herbicldal amounts, 1.e., at rates between about 0.2 10 cotton CT pounds and about 10 pounds per acre. Corn CN TABLE I.PRE/POST EMERGENCE Dosage Compound lbs./ Y Ex. No. acre C G IG- B G TP CT CN BN HERBICIDAL EFFECTIVENESS Method of propagating test species Crabgrass: Digitaria sanguinalis Johnson grass: Sorgum halepense Barnyard grass: Echinochloa crus-galli Turnip: Brassica sp.

Cotton: Gossypium hirsutum var. DPL smooth leaf Corn: Zea mays var. Golden Bantam Bean: Phaseolus vulgaris var. Black Valentine All crop and weed species are planted individually in 3" plastic pots containing potting soil. Four seeds of each of corn, cotton, and snapbeans are seeded to a depth equal to the diameter of the seed. All other species are surface seeded and sprinkled with screened soil in an amount sufiicient to cover the seeds. Immediately after planting, all pots are watered by sub-irrigation in greenhouse trays. Pots for the pre-emergence phase are seeded one day before treatment.

Planting dates for the post-emergence phase are varied so that all the seedlings will reach the desired stage of development simultaneously. The proper stage of seedling development for treatment in the post-emergence phase is as follows:

Grasses: 2 inches in height.

Turnips: 1 or 2 true leaves visible above cotyledons.

Cotton: first true leaf 1 inch in'length expanded cotyledons.

Corn: 3 inches-4 inches in height.

Beans: primary leaves expanded, growing point at primary leaf node.

Method of treatment: Spray applications are made in a hood containing a movable belt and fixed spray nozzle. For passage through the spray hood, one pot of each species (pre-emergence phase) is placed on the forward half of a wooden fiat and one pot of established plants (post-emergence phase) is placed on the rear half of the flat. Treatments are moved to the greenhouse after spraying. Watering during the observation period is applied only by sub-irrigation.

Compounds are screened initially at a rate of application equivalent to eight pounds per acre. Two weeks after treatment the preand post-emergence percent injury is visually rated. Subsequent testing is carried out at 4, 2.1 and 0.5 pounds per acre.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such .variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

1. Herbicidal compounds having the formula:

OzN-

References Cited UNITED STATES PATENTS 3,013,052 12/1961 Richter 260--544 N 3,013,053 12/1961 Richter 260-544 N 3,475,427 10/ 1969 Blank et a1. 260544 N LORRAINE WEINBERGER, Primary Examiner R. D. KELLY, Assistant Examiner US. Cl. X.R. 71-115 Disclaimer 3,812,l84.-R0bert J. T heissen, Westfield, NJ. 2-NITRO-5(HALOPHENOXY) BENZOYL CHLORIDES. Patent dated May 21, 1974. Disclaimer filed Feb. 22, 1984, by the assignee, Rhone-Poulenc Agrochimie. Hereby enters this disclaimer to claims 2, 4 and 5 of said patent.

[Official Gazette April 24, 1984.] 

